Caring for Cane Growers

  • Difficulty Rating: Beginner
Caring for Cane Growers

Among the many forms of woody plants are those often referred to as “cane growers.”

These plants readily send up new, beautiful growth from the root system. Where with a tree, we generally seek to cultivate its original, single trunk by cutting out any “suckers” that emerge from the base of the tree or from the roots, with cane growers, we prune much differently to encourage all that new growth emerging from the roots.

Cane growers generally have several stems – or canes -- emerging from the root system. Each year a cane grower will send up at least a few new canes from the soil. Simultaneously, older canes will become thicker and woodier, and quite often they become more ugly over time.

Consider what happens with a few well-known cane growers if they are left unpruned:

As stems on the canes of Nandina (aka Heavenly Bamboo) age, evergreen leaves and flowers become crowded on the tops of the long, not very pretty stalks. This can make them look gangly and become dangerously top heavy in ice or snow.

Aging canes on plants like many Hydrangea macrophylla (the moppy or lacecap varieties) will produce somewhat interesting exfoliating bark. Unfortunately, little foliage will emerge along these older stems. Instead, most flowers and foliage will form at the end tip of each branch. So, over time, the plant will look empty inside with all the flowers and a few leaves emerging on the tips of leggy, weathered old bark. The plant gets big, but not in a very pretty way.

Older stalks of cane growing barberries not only become unattractive over time, but with some of the showier cultivars, they begin to lose their best foliar features. Berberis ‘Rose Glow’, only produces its trademark speckled cream & rose leaves on new growth. If a cane is old, any leaves that form on it will not be as showy as those on newer canes.

Native twig dogwoods present the same problems. Yes, they can be grown as a single-trunked tree-like plant, but why? That trunk will age, turn a mud-colored brown, losing most of the brilliant reds and yellows that make them winter-garden favorites.

Thicket forming Forsythia are fantastic for wildlife, but in smaller gardens if they’re left to their own devices, they will form long stems that topple over and root themselves when they fall. That means they’ll travel and take over in just a few seasons. Unfortunately, over time, many of those understory stems will begin to die back and offer little of those fantastic early spring blooms that give us hope that winter will end soon.

So, to manage these garden greats and enjoy their best features every season, prune a few of the oldest canes (aka shoots) on the plant to the ground each year. Of course, remove all the dead material before you remove those old, but living canes. Then, take out about 1/3 of the oldest canes, cutting them down to the ground. Remove the smallest, weakest branches as well. This will encourage the plant to send up succulent, fresh, colorful new growth from the earth. So those leggy, older Nandina stems will soon be clothed in fresh new colorful growth. Your thicket of twig dogwood will be brilliantly colored in winter, your hydrangea will look thick and lush, and those barberries will show their stuff come spring.

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Timing your pruning may vary by your region. In the Pacific Northwest, pruning Hydrangea in late summer or fall means you’ll bring in cut flowers to enjoy, and the plant will power up new growth in spring. Cutting down twig dogwood in late winter means you get to enjoy fiery stems in the garden all winter as well as twig wreaths and arrangements before spring. Barberry and Nandina canes may be cut in Fall, but be sure to do it well before a freeze or wait ‘til Spring; just remember they bloom mid-spring, so cut this plant right after flowering so you can enjoy every moment of beauty. Ideally, Forsythia is pruned hard right after it blooms. This will give the plant plenty of time to produce new canes and flower buds for the following spring.

Although roses are grouped among the cane growers, take care cutting all roses hard to the ground. Many roses are grafted – the part below the ground is very adept at doing the plant work below the soil; the part above the ground is hybridized to produce a very showy flower. Each is distinctly different. If you cut your grafted, hybrid rose to the ground, you may end up with a very big surprise from the new canes that emerge – and likely it won’t be a happy surprise.

Not sure if the plant you’re getting ready to prune is a cane grower? Visit the Plant Amnesty website to find a pruning guide, with lists of cane growers specific to each region.